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authorIvan Lipski <ivan.lipski@amd.com>2026-02-25 21:48:36 -0500
committerAlex Deucher <alexander.deucher@amd.com>2026-03-11 14:01:39 -0400
commitbecbab4a5a02156000f3aaff8bb70e8fd3e0d4cf (patch)
tree1aff1f9dc74b239182151b5c15537cfdea040eab
parent33efc6346e8cf75219673fe1ca1916ab40643728 (diff)
drm/amd/display: Check for S0i3 to be done before DCCG init on DCN21
[WHY] On DCN21, dccg2_init() is called in dcn10_init_hw() before bios_golden_init(). During S0i3 resume, BIOS sets MICROSECOND_TIME_BASE_DIV to 0x00120464 as a marker. dccg2_init() overwrites this to 0x00120264, causing dcn21_s0i3_golden_init_wa() to misdetect the state and skip golden init. Eventually during the resume sequence, a flip timeout occurs. [HOW] Skip DCCG on dccg2_is_s0i3_golden_init_wa_done() on DCN21. Fixes: 4c595e75110e ("drm/amd/display: Migrate DCCG registers access from hwseq to dccg component.") Reviewed-by: Aurabindo Pillai <aurabindo.pillai@amd.com> Signed-off-by: Ivan Lipski <ivan.lipski@amd.com> Signed-off-by: Alex Hung <alex.hung@amd.com> Tested-by: Dan Wheeler <daniel.wheeler@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> (cherry picked from commit c61eda434336cf2c033aa35efdc9a08b31d2fdfa)
-rw-r--r--drivers/gpu/drm/amd/display/dc/dccg/dcn21/dcn21_dccg.c21
1 files changed, 20 insertions, 1 deletions
diff --git a/drivers/gpu/drm/amd/display/dc/dccg/dcn21/dcn21_dccg.c b/drivers/gpu/drm/amd/display/dc/dccg/dcn21/dcn21_dccg.c
index 75c69348027e..c4d4eea140f3 100644
--- a/drivers/gpu/drm/amd/display/dc/dccg/dcn21/dcn21_dccg.c
+++ b/drivers/gpu/drm/amd/display/dc/dccg/dcn21/dcn21_dccg.c
@@ -96,6 +96,25 @@ static void dccg21_update_dpp_dto(struct dccg *dccg, int dpp_inst, int req_dppcl
dccg->pipe_dppclk_khz[dpp_inst] = req_dppclk;
}
+/*
+ * On DCN21 S0i3 resume, BIOS programs MICROSECOND_TIME_BASE_DIV to
+ * 0x00120464 as a marker that golden init has already been done.
+ * dcn21_s0i3_golden_init_wa() reads this marker later in bios_golden_init()
+ * to decide whether to skip golden init.
+ *
+ * dccg2_init() unconditionally overwrites MICROSECOND_TIME_BASE_DIV to
+ * 0x00120264, destroying the marker before it can be read.
+ *
+ * Guard the call: if the S0i3 marker is present, skip dccg2_init() so the
+ * WA can function correctly. bios_golden_init() will handle init in that case.
+ */
+static void dccg21_init(struct dccg *dccg)
+{
+ if (dccg2_is_s0i3_golden_init_wa_done(dccg))
+ return;
+
+ dccg2_init(dccg);
+}
static const struct dccg_funcs dccg21_funcs = {
.update_dpp_dto = dccg21_update_dpp_dto,
@@ -103,7 +122,7 @@ static const struct dccg_funcs dccg21_funcs = {
.set_fifo_errdet_ovr_en = dccg2_set_fifo_errdet_ovr_en,
.otg_add_pixel = dccg2_otg_add_pixel,
.otg_drop_pixel = dccg2_otg_drop_pixel,
- .dccg_init = dccg2_init,
+ .dccg_init = dccg21_init,
.refclk_setup = dccg2_refclk_setup, /* Deprecated - for backward compatibility only */
.allow_clock_gating = dccg2_allow_clock_gating,
.enable_memory_low_power = dccg2_enable_memory_low_power,